JP3087015B2 - U-axis machining tool moving device for machine tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machine tool for performing cutting while moving a tool mounted on a front end of a spindle in a direction (U-axis direction) orthogonal to the axis of the spindle.

[0002]

2. Description of the Related Art The above machine tool is provided with a moving device for moving a tool provided at the tip of a spindle in the U-axis direction. As this moving device, as shown in FIG. 10, a rack 43 is formed on the back surface of a tool slide 42 to which a tool 41 is fixed, and a pinion gear 45 in a tool head 44 meshing with the rack 43 is provided on the axis of the spindle 40. A single slide system in which the pinion gear 45 is rotated by the axial movement of the draw rod 46 and the tool slide 42 is moved in the U-axis direction by meshing with the rack 47 at the tip of the drawn rod 46. As shown in FIG. 11, a tool slide 52 for mounting a tool 51 and a counterweight 53 are provided in parallel on a tool head 50, and a serration block 54 provided on the tool slide 52 and the counterweight 53, respectively. Formed in opposite directions to the left and right of the draw rod 55 that moves in the axial direction And with the teeth are meshed, the back-and-forth movement of the draw rod 55, moves the tool slide 52, the counterweight 53
Is moved in the opposite direction to achieve balance.

[0003]

In the former single slide system, the amount of movement of the tool and the number of rotations of the spindle are limited in order to maintain the balance during rotation. Therefore, the latter double slide method is more suitable for maintaining balance during rotation, but on the other hand, it is not possible to reduce the speed of the spindle rotation because the structure is complicated and it is not possible to reduce the size, and ultimately the cutting conditions should be optimally selected. Can not be done. In addition, due to the complexity and excessive size of the above structure, the amount of overhang from the spindle bearing to the tip of the tool is large, and the rigidity of the spindle is inferior.
There is also a problem that it is not suitable for high-speed machining.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a tool for U-axis machining in a machine tool capable of achieving high-speed rotation and achieving good cutting by stabilizing the balance during rotation without making the structure complicated and excessive. In the spindle, a configuration is provided in which a seesaw member having a fulcrum axis serving as a swing center is provided on the axis of the spindle, and a tool can be mounted on a front end of the seesaw member. to one, the rear end portion, a mobile device U-axis machining tool in a machine tool of the rear end portion provided with a swinging means for a predetermined angle inclined from the axis of the spindle, the
Swing means is provided at the rear end of the seesaw member,
Drive pins with serrations in the same direction on the end face
And the drive pin and the spindle
A pair of drive plates movable back and forth in the axial direction of
Holding the drive pin in the drive plate
Provided on the side and meshes with the serrations of the drive pin
And the drive plate is moved back and forth to
Tilting the bupin to make an arc locus about the fulcrum axis
While it is formed by oblique serration, from the fulcrum axis
The distance to the cutting edge of the tool, and the
Set the distance to the axis of the live pin equal, and
On the seesaw member, the fulcrum shaft is arranged in parallel with each other.
Placed, projecting from the seesaw member in opposite directions to each other
Providing a pair of pin members that contact the inner surface of the spindle
The seesaw member is opposite to the cutting side by the tool
It is characterized by being urged to rotate in the direction .

[0005]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a spindle unit in a U-axis processing machine. A spindle 2 is supported by a hexagonal quill 4 supported in a main body 3 so as to be movable back and forth in the axial direction.
The spindle motor 5 for rotating the spindle 2 and the feed screw 6b connected to a draw bar 36 (described later) of the spindle 2 axis via a rotary joint 6a are controlled to rotate.
A tool control motor 6 for moving the draw bar 36 back and forth in the axial direction is provided, and the main body 3 is provided with a feed motor 7 for moving the quill 4 back and forth in the axial direction. In particular, in the spindle unit 1, the hexagonal quill 4 enables stable support of the spindle 2 and high rigidity.

FIGS. 2 to 4 are detailed views of the distal end portion of the spindle 2. The following description will be made with the mounting side of the tool holder 20 as the front side. At the front end of the hollow spindle body 8, a cylindrical housing 9 in which two parts are assembled with bolts 9a, 9a.
Are fixed with four bolts 10, 10,.... As shown in FIG. 6, a circular through hole 12 is formed in the housing 9 at right angles to an oval bottomed hole 11 provided in the axial direction. By closing at 13, a cross-shaped hollow portion is formed inside, and a tool spindle 14 as a seesaw member is accommodated between the hollow portion and the spindle body 8.
The tool spindle 14 is shown in FIG.
It comprises a cylindrical portion 15 at the tip protruding from the housing 9, a flat bar-shaped shaft support 16 at the center, and a rearward swinging portion 17 extending into the spindle body 8, and the central portion accommodated in the bottomed hole 11 of the housing 9. The fulcrum shaft 18 is press-fitted orthogonally into the fulcrum shaft portion 16, and both ends of the fulcrum shaft 18 are axially supported by tapered roller bearings 19, 19 provided in the through-hole 12, thereby swinging about the fulcrum shaft 18. Supported as possible. Further, a base end portion 22 of a tool holder 20 having a tip 21 at a distal end is inserted into a mounting hole 15a of the cylindrical portion 15 at the distal end, and is screwed to a side surface of the cylindrical portion 15 when the tool holder 20 is mounted. The side lock screw 23 comes into contact with a chamfered portion 22 a provided on the side surface of the base end portion 22, and the tool holder 20.
Is integrated with the tool spindle 14. Cylindrical part 15
A base 24 is fitted with a washer 24 having a curved peripheral surface, and an oil seal 25 provided at an opening in front of the housing 9 is in close contact with the washer 24 to seal the inside of the housing 9. Have been. On the other hand, the shaft support 16 has a pair of bottomed holes 26, 26 parallel to the axis of the tool spindle 14.
Are formed in directions opposite to each other, and a headed pin 27 is loosely inserted into each bottomed hole 26 in a direction opposite to each other.
6, a plurality of disc springs 28, 28
.. provided by which the tool spindle 14
The return spring mechanism is configured to urge the shaft 21 in a direction opposite to the tip 21 with respect to the axis of the spindle 2 (the left-hand rotation direction in FIG. 3), that is, in a direction in which cutting resistance is applied.

In the oscillating portion 17, an elongated hole 29 is formed in the axial direction, and a drive pin 30 having serrations 31, 31 formed in the same direction on both end surfaces is fitted behind the elongated hole 29. , On both sides of the drive pin 30,
As shown in FIG. 8, a pair of drive members as guide members each provided with an inclined serration 33 which is engaged with the serration 31 of the drive pin 30 and inclined (here, about 11 degrees) with respect to the axis of the spindle 2. Plate 32,
32 is a spindle body 8 with the swinging part 17 interposed therebetween.
And the front ends thereof are connected by connecting pins 34 passing through the elongated holes 29 and bolts 34a, 34a (FIG. 7). Further, both rear ends of the drive plates 32, 32 are connected to the joint plates 3 respectively.
The joint plate 35 is fixed to the draw bar 5 by bolts 35a, 35a. The joint plate 35 is connected to the draw bar 36 by a petal-type connecting portion 37 provided at the tip of a draw bar 36 that can move back and forth in the axial direction at the axis of the spindle 2. It is integrated (FIG. 9). So here, drawbar 3
6, the joint plate 35 and the drive plates 32, 32 can move back and forth within the hollow portion of the spindle body 8 with a predetermined stroke, and the drive pins 30 are moved with the front and rear movements of the drive plates 32, 32. Guided by the inclined serrations 33, 33, swings along an arc locus centered on the swing center O. Similarly, the swing portion 17 is swung, and the tool spindle 14 is set with the swing center O as a fulcrum. Will be rocked. Especially here, the distance L ₁ from the swing center O to the tip 21, since the set equal to the distance L ₂ to the center of the drive pin 30 from the swing center O, the same movement as the movement amount of the drive pin 30 The chip 21 will get the quantity. 38, 38
Is a supply path of the cutting fluid, from the spindle body 8 through the housing 9 to the caps 13, 13.
3 are connected to both ends of the fulcrum shaft 18 and merge at the swing center O, and then guided along the axis from the rear end to the front end of the tool holder 20 and supplied from the outlet 20a. As a result, even with a small-diameter work, high-pressure cutting fluid is projected from the cutting edge of the tool holder 20 to effectively discharge chips and cool the cutting edge, thereby stabilizing the processing diameter and improving the processing accuracy. 39 is a cylindrical portion of the tool spindle 14 for adjusting the balance by changing the size of the tool holder 20.
The balance ring is press-fitted into

In the U-axis processing machine configured as described above, the tool spindle 14 for mounting the tool holder 20
Has a seesaw type structure that swings about a fulcrum shaft 18, so that when the draw bar 36 is moved in the axial direction by the NC control of the tool control motor 6, the tool holder 20 and the tool spindle 14 are moved together as described above. Also swings along an arc locus about the swing center O. That is, when the draw bar 36 is moved forward, the drive pin 30 moves in the direction of arrow A shown in FIG. 3 and the tool holder 20 is moved in the direction of arrow a at the same angle to obtain the amount of movement from the axis to the direction of the U axis. Can be When the drawbar 36 is retracted, the drive pin 30 moves in the direction of arrow B, and the tool holder 20 moves in the direction of arrow b at the same angle, so that the amount of movement in the opposite direction is obtained (this U-axis stroke is Up to 25mm). As described above, according to the present embodiment, by employing the tool spindle 14 as the seesaw member, the balance of the spindle 2 can be constantly maintained even when the tool holder 20 is moved in the U-axis direction, and an extra balance weight or the like is used. Eliminates the need. Therefore, simplification and compactness of the tip of the spindle can be achieved, the speed of spindle rotation can be increased, and optimal cutting conditions can be selected. In addition, the rigidity of the spindle is improved due to the downsizing, so that it can be suitably performed even with a small diameter processing. Incidentally, the conventional spindle as shown in FIGS. 10 and 11 has a rotation speed of about 3000 rpm, but the spindle 2 can obtain a rotation speed of 8000 rpm or more, and a cutting tool for high-speed machining such as diamond and CBN. However, efficient use can be achieved under optimal conditions.

Further, in the above-described embodiment, a structure is employed in which the tool spindle 14 is swung by the front-rear movement of the drive plates 32, 32 having the inclined serrations 33, 33 for holding the serrations 31 of the drive pins 30. Therefore, the swing operation with high accuracy is possible.
Further, the shaft support 16 at the center of the tool spindle 14 employs a return spring mechanism including a plurality of disc springs 28, 28 and a headed pin 27 to apply the urging force in the same direction as the cutting resistance. Can be removed, and the followability of the tool holder 20 is suitably maintained. Similarly, by adopting a tapered roller bearing 19 for the bearing of the fulcrum shaft 18 to enable stable support without generating a gap or rattling, the reliability of the followability and reproducibility of the tool is further improved. It is like that.

The above embodiment can be appropriately modified in design without departing from the spirit of the present invention, and a coil spring can be used for the return spring mechanism. Tapered roller bearing 1 used for bearing of fulcrum shaft 18
Instead of 9, a ball bearing, a metal bearing, or the like may be used. Further, the seesaw structure of the tool spindle is not limited to the U-axis machine, but can be applied to a U center tool of a machining center or the like.

[0011]

As described above, according to the present invention, the U-axis movement of the tool can be performed in a stable state with a simple structure without disturbing the balance of the spindle or using a counterweight or the like. Compactness can be achieved. Therefore, the spindle can be rotated at a high speed, and suitable cutting can be performed, such as an increase in accuracy and a reduction in time, so that the spindle can be used without problems even in small-diameter processing. Especially the rocking means,
A drive pin having serrations and a pair of drives;
Eve plate and the tilt plate provided on the drive plate
And a seesaw member
Turn the seesaw member in the direction opposite to the cutting
Providing a pair of pin members that biases the
Precise swing operation and backlash prevention in addition to maintenance
Therefore, the processing accuracy can be further improved.

[Brief description of the drawings]

FIG. 1 is an overall view of a spindle unit.

FIG. 2 is an explanatory view of a spindle as viewed from the front.

FIG. 3 is an explanatory sectional view taken along line AA.

FIG. 4 is a sectional view taken along line BB.

FIG. 5 is an explanatory diagram of a seesaw structure.

FIG. 6 is a sectional view taken along line CC.

FIG. 7 is an explanatory sectional view taken along line DD.

FIG. 8 is a sectional view taken along line EE.

FIG. 9 is a sectional view taken along line FF.

FIG. 10 is an explanatory view showing a conventional tool moving device.

FIG. 11 is an explanatory view showing a conventional tool moving device.

[Explanation of symbols]

1. Spindle unit, 2. Spindle, 3.
Main body, 4 quill, 5 spindle motor, 6 tool control motor, 7 feed motor, 8 spindle body, 9 housing, 14 tool spindle, 1
5 · · · cylindrical part, 16 · · · shaft support part, 17 · · · swing part, 18
..Support shaft, 20..Tool holder, 27..Pin with head, 28..Belleville spring, 30..Drive pin, 32 ..
Drive plate, 33 ・ ・ Slant serration, 34 ・
・ Connection pin, 35 ・ Joint plate, 36 ・ Drawbar, 39 ・ Balance ring.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-79507 (JP, A) JP-A-3-196905 (JP, A) JP-A-57-13106 (JP, U) JP-A-37-107 490 (JP, Y1) (58) Field surveyed (Int. Cl. ⁷ , DB name) B23Q 5/34 B23B 29/034

Claims (1)

(57) [Claims] 1. A seesaw member having a fulcrum axis serving as a swing center on an axis of the spindle is provided in a spindle, and a tool can be attached to a front end of the seesaw member. A moving device for a U-axis machining tool in a machine tool provided with rocking means for tilting the rear end portion at a predetermined angle from the axis of the spindle, wherein the rocking means is provided at a rear end portion of the seesaw member. Provided
Drive with serrations in the same direction on both ends
Pin and both ends of the drive pin, and
A pair of drive plates that can move back and forth in the axial direction of the dollar
And the drive pin of the drive plate
Serration of the drive pin provided on the holding side
The drive plate is moved forward and backward to
Move the live pin in an arc locus about the fulcrum axis.
While the fulcrum shaft is formed
And the distance from the fulcrum axis to the cutting edge of the tool.
Set the distance between the drive pin and the shaft center equal, and
Parallel to each other with the fulcrum axis interposed between the seesaw members.
And project from the seesaw member in opposite directions to each other
To provide a pair of pin members that contact the inner surface of the spindle.
Then, the seesaw member is opposed to the cutting side by the tool.
A moving device for a U-axis machining tool in a machine tool, which is biased to rotate in the opposite direction .